Document Type
Article
Publication Date
2023
Journal
Front Neurosci
Volume
17
First Page
1074730
Last Page
1074730
URL with Digital Object Identifier
https://doi.org/10.3389/fnins.2023.1074730
Abstract
Water diffusion anisotropy MRI is sensitive to microstructural changes in the brain that are hallmarks of various neurological conditions. However, conventional metrics like fractional anisotropy are confounded by neuron fiber orientation dispersion, and the relatively low resolution of diffusion-weighted MRI gives rise to significant free water partial volume effects in many brain regions that are adjacent to cerebrospinal fluid. Microscopic fractional anisotropy is a recent metric that can report water diffusion anisotropy independent of neuron fiber orientation dispersion but is still susceptible to free water contamination. In this paper, we present a free water elimination (FWE) technique to estimate microscopic fractional anisotropy and other related diffusion indices by implementing a signal representation in which the MRI signal within a voxel is assumed to come from two distinct sources: a tissue compartment and a free water compartment. A two-part algorithm is proposed to rapidly fit a set of diffusion-weighted MRI volumes containing both linear- and spherical-tensor encoding acquisitions to the representation. Simulations and
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This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License
Notes
PMID: 36960165
PMCID: PMC10027922
DOI: 10.3389/fnins.2023.1074730